I'm So Scared ..

So basically . Idk if I'm pregnant or have some type of infection because I was just on the 5 day of my Birth Control pill and my boyfriend literally came inside me after I told him NOT TOO. I feel horrible. My stomach hurts a bit, I was feeling super sick last night like if I was getting a cold and I had a headache. I searched up the symptoms as too why I'm feeling this way and it said it could either be Pregnancy Symptoms or HIV. I don't think it's HIV because i literally have sex with him almost every day and it's always unprotected sex but I'm still super worried about it. Is his semen making me sick since he did ejaculate inside me?? What should I do, I'm stressing so much and I can't help but cry. I'm only 18.